Black Rot. Black rot is likely to affect your jalapeno peppers if you leave them on the plant to ripen until they turn red. ... It usually occurs if there is too much moisture from rain or excessive watering around your ripening jalapeno plants.

What causes jalapeno peppers to turn black?

Maturity. Jalapenos turning black on the plant are a natural part of the growth and ripening process of the pepper. In fact, this is a signal that it may be time to harvest the jalapeno. The pepper should be picked when it has taken on a blackish-green color.

Are jalapenos bad when they turn black?

Black rot is something that can turn jalapeno peppers black as well. Sometimes when you leave jalapeno peppers on the plant to ripen until they turn red this will occur. This is a type of rot that impacts red peppers that have been completely ripened.